Protein molecules are composed of long chains of?

They are composed of long chains of amino acids.

The building blocks of protein are amino acids. Amino acids are organic molecules made up an alpha (center) carbon atom which is linked to an amino group, a carboxyl group, a hydrogen atom and  a variable component  known as a side chain.

Amino acids are joined to each other by peptide bonds  to form either a short chain called an oligopeptide or  a long chain called a polypeptide.  These chains are what forms the protein.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation:

the wires in the toaster turning red and the toast crisping and turning brown